A cable seal is a cable which is looped into a bight and extended through a lock mechanism. They are expendable. Typically, they are installed to close or seal a container and to indicate that the container, once sealed, has not been opened while in shipment. Generally, sealing is done at the time the container is filled. Several types of containers are provided with seals. It is not uncommon to seal a trailer pulled by a truck on the highway. The seal is attached at the back doors and holds the two doors together. To be sure, it is not provided for structural strength but rather for showing, at arrival, that the contents within the trailer have not been tampered with. Another area in which seals find great application is the shipment of various liquids. Expensive lubricants, the essence of perfumes and the like are typically placed in sealed liquid container. Again, they are protected by the seal especially in the sense that it provides an indication that no tampering has occurred. Tampering may involve theft or adulteration. In all instances, the tampering is indicative of problems in the shipping procedure. It is highly desirable that tampering be avoided. Moreover, by avoiding tampering, the cargo behind the seal is deemed to be correctly counted and to have the correct or intended purity. Therefore, the attachment of a seal forms an indication of product security, product purity and great reliance is placed on the seal remaining intact at the destination. If the seal is unbroken, the purchaser typically is willing to pay the full price for the merchandise protected by the seal. If the seal is unbroken, the purchaser is well able to protect and watch over the goods and merchandise protected by the seal.
While seals go back over time, even to the time at which appointed merchants would seal containers using sealing wax with a signet ring, the present day context of the seal of this disclosure particularly deals with theft or adulteration during shipment just as the case 1,000 years ago. Consider a very common example of manufacturing a concentrate which is shipped from a single plant and distributed around the world. This is particularly true with the essence of fragrances or flavors. It is common in the manufacture of food condiments, perfumes, drinks and the like to make and ship a highly concentrated mixture. At the destination, it is diluted with an inexpensive liquid (water, milk, alcohol and so on). At the time of mixing, it is important to know that the product protected by the seal is pure.
Seal tampering is to be distinguished from overt theft. It is easy enough for a thief with the proper hand tools to cut a seal and to throw it away. In that instance, the absence of the seal is indicative of penetration into the closed chamber where the cargo is located. That, however, is not the situation in this instance. In this instance, the protection is important where the seal might have been tampered with. In other words, while the seal is still on the container, the purchaser or recipient may have serious questions based on a quick visual inspection of the seal. The question always comes down simply to one of appearance, namely, does the seal look as though it was tampered with. The present disclosure sets forth a seal which can withstand and indeed resist a tremendous amount of tampering. Assume for purposes of setting forth the problem that a malfeasant with ample time can attack the seal on a concentrated food or drink syrup. In that instance, the goal might well be adulteration or theft of a portion of the cargo. It is important that the seal be constructed so that it resists to the uttermost any attempt to defeat the seal. Most attacks on a seal involve an effort to work the cable, typically by wiggling and jiggling so that the cable feeds back through the seal mechanism. This disclosure sets forth a device which defeats that. Moreover, it is a device which can withstand a tremendous amount of wiggling and jiggling, grasping the bight of the cable and working it back and forth, all to no avail. The seal of the present disclosure, therefore, is resistant to all types of penetration or entry. It is especially resistant to entry by a shaped pointed sleeve. The seal is constructed with a woven cable. The cable, having a nominal diameter, is looped into a bight and the free end is forced through the seal and grasped. A criminal might readily try to work into the seal mechanism to defeat it by forming a tool which is thin wall metal folded as a 180.degree. sleeve or funnel which fits about the cable. The pointed end is stabbed into the locked housing. The goal is to somehow defeat the works on the interior, thereby enabling the cable to be pulled free. That tampering simply is defeated by the apparatus of this disclosure.
This disclosure sets forth a seal with a lock mechanism that is completely resistant to any type of penetration. The penetration brought about by the tool just mentioned will not defeat the equipment. The cable, placed in the housing, is grabbed and held firmly. So to speak, the cable is held from several sides at several locations in the housing. This provides enhanced clamping of the woven wire cable so that no tampering is inflicted through the use of burglar tools of any sort or type.
The apparatus of this disclosure is a lock mechanism equipped with this sort of cable gripping mechanism is not readily or easily defeated. Indeed, the lock mechanism set forth for this cable seal is, for all practical purposes, tamper proof. The present disclosure sets forth a mechanism which threads the free end of the cable through a housing. On the interior, the housing supports a rotatable circular member. It is free to rotate in the housing. It supports a grip mechanism which grabs and holds the free end of the cable. The cable is pinched or clamped. Pulling the cable out of the housing in the wrong direction is therefore prevented because the clamp mechanism gets tighter when the cable is pulled in that direction. It is a one way clamp. The clamp is implemented by positioning a roller in a groove, the roller being caught or pinched in the groove with a tapered face. The tapered face changes the gap or span in which the rolling disk is captured, thereby positioning the tapered face so that the disk pinches against the cable. An improved enhancement contemplates the installation of three such grooves with three such disks in them. In one embodiment they can all clamp the cable at the same relative height; in another embodiment, different size diameter rollers are installed to achieve the clamping action. In another aspect, identical disks can be used but the grooves are cut at different radial locations. In the latter, the grooves are provided with different relative positions so that the cable is gripped at spaced locations along the cable. This helps hold in a different way. It forces the cable, contacted at different locations, to distort and bend in such a way that the cable is pinched indefinitely against release.
In another aspect, the disks are forced against the tapered face by a resilient spring. One spring is installed coaxially about the cable so that the bottom loop of the spring bears against multiple disks and forces them inwardly against the cable thereby increasing the bight each disk takes when jammed against the cable. The cable is therefore gripped in a better fashion. Once the free end of the cable is looped into a bight and threaded through the housing, release, using this mechanism, is impossible, and defeat by burglar tools and the like is not possible. Therefore, this construction helps overcome entry by burglars, thieves or other malfeasants.
The present device is summarized as a tamper resistance cable seal having a housing which attaches to the dead end of the cable and an opening for receiving the free end. Once the free end is threaded through the device, it locks and that prevents further retrieval. The present housing encloses a circular insert which is free to rotate. No matter how many turns are imparted in either direction, the cable is held constantly without rotational slippage. The insert within is mounted on individual balls which define a bearing raceway. A coil spring forces the insert against the bearings. In addition, the cylindrical insert is formed with a radial slot having a tapered face. The taper on the face guides a spring forced disk to a specified depth in the tapered groove. This initiates clamping of the cable by the disk extending from the tapered groove. Different embodiments use different points of contact achieved by a disk in each of multiple grooves, the optimum being three grooves and three disks located at 120.degree. spacing so that the cable is gripped on three sides.
It has been discovered that one improvement which enables even greater resistance against working the cable free can be obtained in the following fashion. It is desirable to avoid this wiggling release problem attempted by a thief by increasing the strength of the spring in the cable lock housing, the spring bearing against the roller or disk which bears against the cable. If the spring is made unduly weak, defeat is obtained by patient working of the cable. If the spring is made stronger, that will not happen. By making the spring much stronger than that threshold requirement, the spring jams the disk without doubt or uncertainty in the tapered groove for the disk. That assures that the cable is locked, but it is accomplished at a difficult price. One difficulty arising from that is the difficulty of initially threading the cable. As will be discussed, it is somewhat difficult to dislodge the disk when striking at the tangential edge where the cable is guided into the housing by the tapered faces defining the chamber which holds the disk or roller. The present disclosure overcomes this and enables a very strong spring to be used.
Another embodiment of the present disclosure uses a pair of the rollers or disks mentioned above. They are installed at right angles to each other with respect to the movable insert within the housing. The insert is a cylindrical body with a central or axial passage through the cable. It is positioned immediately adjacent to a pair of the flat disks which are captured in tapered grooves. The two grooves, in cross section, are positioned at right angles. The two disks jam the cable against the opposite side of the central passage for the cable. The two disks are preferably located at different heights with different tapered slots so that they pinch at different locations along the length of the cable. In effect, this defines (in cross section) a V-shaped profile having the point of the V centered at the center line of the insert body.
In an embodiment worth noting, that V-shaped cut on the interior of the insert is readily moved over to the side of the insert. In that instance, the insert is built substantially without the cylindrical housing. In the first embodiment, the insert is a round cylindrical body which fits within a housing, and the center line axis of the housing and insert defines the point of insertion of the free end of the woven cable. Using the insert only, the hole is offset from the center and the V-shaped internal cut defined by the intersecting right angle slots is located so that the same size cable and the same size rollers are cooperatively offset in an insert body of decreased diameter. By this approach, both cable ends can be terminated in the insert body (meaning the two cable ends engage the insert without a rotative movable housing).